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前不久网上有人问如何在java代码里根据屏幕宽度动态设定每一行的单元格数。百度了好久，没结果，结果自己认真分析，实现了这个功能。
gridview可以在xml布局里面设定每一个单元的宽度，以及手机屏幕的宽度来确定，一行能够容纳的单元格数。怎样在java代码里，动态设定一行的单元格数呢？
package com.lin.test;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.WindowManager;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
public class SecondActivity extends Activity{
GridView gridView;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
init();
List<HashMap<String,Object>> list=new ArrayList<HashMap<String,Object>>();
for(int i=0;i<MyProject001Activity.size;i++){
HashMap<String, Object> mp= new HashMap<String,Object>();
mp.put("image", R.drawable.ic_launcher);
mp.put("text","第"+(i+1)+"关");
list.add(mp);
}
SimpleAdapter simpleAdapter=new SimpleAdapter(getApplicationContext(), list, R.layout.item, new String[]{
"image","text"
}, new int[]{
R.id.imageView,R.id.tv
});
gridView.setAdapter(simpleAdapter);
gridView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(), arg2, 3).show();
}
});
}
private void init() {
// TODO Auto-generated method stub
gridView=(GridView) findViewById(R.id.GridView);
WindowManager wm = this.getWindowManager();//获取WindowManager
int width = wm.getDefaultDisplay().getWidth();//获取到屏幕宽度
double width2=width/Math.sqrt(MyProject001Activity.size);//用屏幕的宽度比上单元格的个数，就是每一个单元格的宽度
System.out.println("width"+width);
System.out.println("width2"+width2);
gridView.setColumnWidth((int) width2);//gridview动态设置每一个单元格的宽度
}
}
second.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
>
<GridView
android:id="@+id/GridView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:numColumns="auto_fit"
android:stretchMode="columnWidth"
android:gravity="center">
</GridView>
</LinearLayout>
MyProject001Activity.java
package com.lin.test;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class MyProject001Activity extends Activity {
/** Called when the activity is first created. */
EditText tv;
public static int size=0;
//定义静态变量，作为设定的每一行的单元格数。
//其实可以通过界面跳转intent传值，这里我简化了
Button button;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
init();
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
final int bianchang= Integer.parseInt(tv.getText().toString());
size=bianchang*bianchang;
startActivity(new Intent(MyProject001Activity.this,SecondActivity.class));
}
});
}
private void init() {
// TODO Auto-generated method stub
tv= (EditText) findViewById(R.id.tv);
button= (Button) findViewById(R.id.button);
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/tv"
android:hint="正方形的边长？"
/>
<Button
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/button"
android:text="提交"
/>
</LinearLayout>
item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
android:layout_gravity="center"
/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/tv"
android:layout_gravity="center"
/>
</LinearLayout>
效果图：
在界面A，输入5，点击提交
在界面B保证长行列的单元格数相同
最后别忘了清单文件
<activity android:name=".SecondActivity"/>